zlacker

You raise a good point. I found this page from the Norway tax authority. (In a previous post, I noted that Norway had had a wealth tax for a long time. About 1%.)

    > When calculating wealth tax, you must include any assets that you own at the end of the year. These assets must generally be valued at what the asset is worth on the open market. However, an exception is made in the case of housing, and a lower value, known as the tax value, must be used when calculating wealth tax.  

Ref: https://www.skatteetaten.no/en/rates/tax-value-of-housing/

Two things stand-out to me:

(1) "assets must generally be valued at what the asset is worth on the open market". I guess there will be GAAP accounting rules about how to value less liquid assets. Tradable securities are easy to value; other things, like artwork are less easy to value. In the case of a car, an accountant could reasonably use an online used car marketplace to find a value. (The US has something called the Kelley Blue Book.)

(2) "an exception is made in the case of housing". It sounds like there is a totally different set of rules for taxing housing (land+building).